The existing polyurea lining had failed, leaving the concrete tanks unprotected from the abrasive agents contained within the tanks. The abrasive action in these tanks is particularly extreme as glass is contained in the product.
We proposed the lining of the tanks with a glass flake reinforced epoxy from Chemco International due to its excellent abrasion resistance.
Initially the failed lining was removed by hand, using vibration damped breakers to remove stubborn sections.
Testing for chloride contamination and high pressure water rinse
Before blasting works commenced the concrete was tested for chloride contamination and was found to be high. A high pressure fresh water rinse was put in place to reduce these prior to blasting works commencing.
The concrete was prepared by abrasive blasting to remove laitance and contamination. In doing so this exposed extensive honeycombing in the concrete which had to be filled prior to the application of the abrasion resistant tank lining.
To do this we applied Remmers Sulfatex grout using our Graco M680 mortar pump and trowelled to a float finish. The tank was then dried out using indirect oil fired heating to bring the moisture content of the concrete below 6% as required for the damp tolerant epoxy primer.
Remmers Epoxy MT100 was then spray applied to all surfaces and back rolled to force into pores and profile.
Applying the Chemco tank lining using RA500M
The first coat of the Chemco abrasion resistant tank lining was then applied in the form of RA500M at a thickness of 500 microns. As per good tank lining practice this was applied in a contrasting colour to the second coat to aid application.
The second coat of the Chemco Tank lining was then applied in the same manner as the first, to achieve a total lining thickness of 1000 microns.
As part of our standard tank lining quality assurance the lining was spark tested to check for pin holing and porosity. Where found these were marked with chalk prior to touching in using the same materials.
Finally to offer further protection against the glass contained within the product the area opposite the mixer was clad with 2mm thick stainless steel sheeting which was both mechanically fixed and chemically bonded using a thixotropic epoxy adhesive.